Here we read the currently flashed firmware version of both
primary and secondary firmware and then compare it with
version of firmware file to determine if flashing is required.

Signed-off-by: Ajay Gupta <[email protected]>
---
Changes from v1:
        - Updated commit message
        - Squashed patch 6/7 of v1 into it
        - Dropped dev_dbg prints
        - Dropped uses of bitfield min/maj

 drivers/usb/typec/ucsi/ucsi_ccg.c | 153 ++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c 
b/drivers/usb/typec/ucsi/ucsi_ccg.c
index b1fadec9172b..9fbd7f2c04fb 100644
--- a/drivers/usb/typec/ucsi/ucsi_ccg.c
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -9,6 +9,7 @@
  */
 #include <linux/acpi.h>
 #include <linux/delay.h>
+#include <linux/firmware.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -68,6 +69,29 @@
 #define FW2_METADATA_ROW        0x1FE
 #define FW_CFG_TABLE_SIG_SIZE  256
 
+static int secondary_fw_min_ver = 41;
+
+enum enum_fw_mode {
+       BOOT,   /* bootloader */
+       FW1,    /* FW partition-1 (contains secondary fw) */
+       FW2,    /* FW partition-2 (contains primary fw) */
+       FW_INVALID,
+};
+
+enum enum_flash_mode {
+       SECONDARY_BL,   /* update secondary using bootloader */
+       PRIMARY,        /* update primary using secondary */
+       SECONDARY,      /* update secondary using primary */
+       FLASH_NOT_NEEDED,       /* update not required */
+       FLASH_INVALID,
+};
+
+static const char * const ccg_fw_names[] = {
+       /* 0 */ "ccg_boot.cyacd",
+       /* 1 */ "ccg_primary.cyacd",
+       /* 2 */ "ccg_secondary.cyacd"
+};
+
 struct ccg_dev_info {
 #define CCG_DEVINFO_FWMODE_SHIFT (0)
 #define CCG_DEVINFO_FWMODE_MASK (0x3 << CCG_DEVINFO_FWMODE_SHIFT)
@@ -94,6 +118,20 @@ struct version_info {
        struct version_format app;
 };
 
+struct fw_config_table {
+       u32 identity;
+       u16 table_size;
+       u8 fwct_version;
+       u8 is_key_change;
+       u8 guid[16];
+       struct version_format base;
+       struct version_format app;
+       u8 primary_fw_digest[32];
+       u32 key_exp_length;
+       u8 key_modulus[256];
+       u8 key_exp[4];
+};
+
 /* CCGx response codes */
 enum ccg_resp_code {
        CMD_NO_RESP             = 0x00,
@@ -709,6 +747,121 @@ static int ccg_cmd_validate_fw(struct ucsi_ccg *uc, 
unsigned int fwid)
        return 0;
 }
 
+static bool ccg_check_vendor_version(struct ucsi_ccg *uc,
+                                    struct version_format *app,
+                                    struct fw_config_table *fw_cfg)
+{
+       struct device *dev = uc->dev;
+
+       /* Check if the fw build is for supported vendors.
+        * Add all supported vendors here.
+        */
+       if (app->build != (('n' << 8) | 'v')) {
+               dev_info(dev, "current fw is not from supported vendor\n");
+               return false;
+       }
+
+       /* Check if the new fw build is for supported vendors
+        * Add all supported vendors here.
+        */
+       if (fw_cfg->app.build != (('n' << 8) | 'v')) {
+               dev_info(dev, "new fw is not from supported vendor\n");
+               return false;
+       }
+       return true;
+}
+
+static bool ccg_check_fw_version(struct ucsi_ccg *uc, const char *fw_name,
+                                struct version_format *app)
+{
+       const struct firmware *fw = NULL;
+       struct device *dev = uc->dev;
+       struct fw_config_table fw_cfg;
+       u32 cur_version, new_version;
+       bool is_later = false;
+
+       if (request_firmware(&fw, fw_name, dev) != 0) {
+               dev_err(dev, "error: Failed to open cyacd file %s\n", fw_name);
+               return false;
+       }
+
+       /*
+        * check if signed fw
+        * last part of fw image is fw cfg table and signature
+        */
+       if (fw->size < sizeof(fw_cfg) + FW_CFG_TABLE_SIG_SIZE)
+               goto not_signed_fw;
+
+       memcpy((uint8_t *)&fw_cfg, fw->data + fw->size -
+              sizeof(fw_cfg) - FW_CFG_TABLE_SIG_SIZE, sizeof(fw_cfg));
+
+       if (fw_cfg.identity != ('F' | 'W' << 8 | 'C' << 16 | 'T' << 24)) {
+               dev_info(dev, "not a signed image\n");
+               goto not_signed_fw;
+       }
+
+       /* compare input version with FWCT version */
+       cur_version = app->build | app->patch << 16 | app->ver << 24;
+
+       new_version = fw_cfg.app.build | fw_cfg.app.patch << 16 |
+                       fw_cfg.app.ver << 24;
+
+       if (!ccg_check_vendor_version(uc, app, &fw_cfg))
+               goto not_supported_version;
+
+       if (new_version > cur_version)
+               is_later = true;
+
+not_supported_version:
+not_signed_fw:
+       release_firmware(fw);
+       return is_later;
+}
+
+static int ccg_fw_update_needed(struct ucsi_ccg *uc,
+                               enum enum_flash_mode *mode)
+{
+       struct device *dev = uc->dev;
+       int err;
+       struct version_info version[3];
+
+       err = ccg_read(uc, CCGX_RAB_DEVICE_MODE, (u8 *)(&uc->info),
+                      sizeof(uc->info));
+       if (err) {
+               dev_err(dev, "read device mode failed\n");
+               return err;
+       }
+
+       err = ccg_read(uc, CCGX_RAB_READ_ALL_VER, (u8 *)version,
+                      sizeof(version));
+       if (err) {
+               dev_err(dev, "read device mode failed\n");
+               return err;
+       }
+
+       if (memcmp(&version[FW1], "\0\0\0\0\0\0\0\0",
+                  sizeof(struct version_info)) == 0) {
+               dev_info(dev, "secondary fw is not flashed\n");
+               *mode = SECONDARY_BL;
+       } else if (version[FW1].base.build < secondary_fw_min_ver) {
+               dev_info(dev, "secondary fw version is too low (< %d)\n",
+                        secondary_fw_min_ver);
+               *mode = SECONDARY;
+       } else if (memcmp(&version[FW2], "\0\0\0\0\0\0\0\0",
+                  sizeof(struct version_info)) == 0) {
+               dev_info(dev, "primary fw is not flashed\n");
+               *mode = PRIMARY;
+       } else if (ccg_check_fw_version(uc, ccg_fw_names[PRIMARY],
+                  &version[FW2].app)) {
+               dev_info(dev, "found primary fw with later version\n");
+               *mode = PRIMARY;
+       } else {
+               dev_info(dev, "secondary and primary fw are the latest\n");
+               *mode = FLASH_NOT_NEEDED;
+       }
+       return 0;
+}
+
 static int ucsi_ccg_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
 {
-- 
2.17.1

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